This invention generally relates to a door closing apparatus, and more particularly, relates to a door closing apparatus having modular characteristics in that a self-contained hydraulic damping assembly thereof is selectively releasably connected to a closing spring assembly.
Door operators or control devices are commonly used to regulate or control the closing cycle of a door. A door operator may simply consist of a spring which interconnects the door through a portion of the door frame. The spring is mounted within the door or an extension thereof in a manner such that the spring is compressed between a pair of spring blocks when the door is opened. When the opened door is released, the spring, in accordance with its spring constant, exerts a closing force on the door. The closing force may be selected in advance to match the characteristics of the door by selecting a desired spring constant.
Often, the spring may exert too strong of a closing force upon the door. To regulate the closing force, a damping assembly is typically used and made a part of the spring closing assembly to provide a means to dampen, or regulate, the closing force exerted on the door by the spring and slow down the rate of closure of the door. A door closing apparatus using both a damping assembly and spring assembly is referred to as a "combination" door operator or control device. The damping force prevents the door from closing too quickly an inadvertently catching persons between it and the door frame, or from the door causing any damage to door frame.
A typical hydraulic damping mechanism used in a door control apparatus includes a piston which reciprocates within a cylinder disposed within a housing of the door control apparatus. The piston reciprocates within the cylinder to displace fluid in and out of the cylinder into a nearby fluid reservoir in accordance with the movement of the door. The incompressible nature of the fluid acts to dampen the closing force applied to the door by spring. Combination door operators which utilize a spring closing mechanism and a hydraulic damping mechanism are commonly made as a one-piece structure. In instances where the hydraulic component fails, the fluid leaks past seal assemblies. The leakage of fluid not only may stain either the door frame or individuals using the door, but also renders the door control apparatus useless in that the hydraulic component can no longer dampen the closing force of the door. Whenever the hydraulic assembly or the spring assembly fails in a combination door operator in which the hydraulic component is integrated into the operator, such a failure necessitates that the entire door control apparatus be removed from the door and replaced. Because the mechanical components of the door control apparatus, such as the closing spring and any gear mechanisms associated therewith, may last virtually indefinitely when compared to the hydraulic damping component, the removal and replacement of the entire door control apparatus is wasteful and expensive.
A need therefore exists for a combined door control apparatus which is modular in nature and allows the easy removal and replacement of the hydraulic damping components(s) alone from the apparatus. The present invention is thus directed to a door control apparatus which overcomes the aforementioned disadvantages and permits the hydraulic assembly of the combined door control apparatus to be easily removed as a unit from the control apparatus.
In this regard, a door control apparatus constructed in accordance with the principles of the present invention utilizes a closing spring assembly and a hydraulic damping assembly that are operatively, and selectively releasably connected at a quick release connection point, to give the door control apparatus a modular nature. The hydraulic assembly has a self-contained construction which includes a fluid cylinder and a piston reciprocatably mounted therein. A fluid reservoir is disposed proximate to the cylinder and communicates therewith by way of a plurality of fluid transfer passages. The rod of the piston extends out of the cylinder and includes an engagement member which is received by a receptacle which adjoins one of the spring blocks. Such a quick release connection may include a ball-and socket-joint in which the ball member extends from the piston rod into the socket member which is either contained within the spring block or adjacent thereto. The spring assembly may be a conventional assembly and include a rack and pinion gear assembly interconnected to a spring retained in place between and compressible between two opposing spring blocks.
Accordingly, it is an object of the present invention to provide an improved combined door control apparatus.
It is another object of the present invention to provide a combination door operator having a modular construction in which a separate spring assembly and a separate hydraulic damping assembly are selectively releaseably interconnected with each other, the interconnection permitting the damping assembly to be disconnected from the spring assembly and removed as a single unit from the door control apparatus in a reliable manner and in a minimum amount of time.
Still another object of the present invention is to provide a door control device operator for a balanced door in which the control device includes a spring-biased closing assembly operatively and selectively releaseably engaged to a damping assembly, the damping assembly having a fluid-filled cylinder, a piston slidably disposed therein and a fluid reservoir communicating with the cylinder by way of multiple fluid transfer ports extending between a wall separating the cylinder from the reservoir, the fluid transfer ports being aligned along a longitudinal axis of the fluid piston, each of the ports having means for adjusting the size of the ports so as to control the rate of fluid flow between the fluid reservoir and the fluid cylinder, the damping assembly being further contained within its own housing, a portion of the piston extending through the damping housing, the piston operatively engaging the spring assembly at a quick release connection, whereby the damping assembly can be inserted into and removed from the door control apparatus as a unit.
These and other objects and advantages of the present invention will be clearly understood through a consideration of the following detailed description wherein like reference numerals refer to like parts.